Hair Pull Test: The Diagnostic Procedure Anyone Can Perform

The hair pull test is one of the simplest and most useful bedside diagnostic procedures in dermatology. The technique involves gently grasping 50 to 60 hairs between thumb and forefinger and applying steady traction along the hair shaft. The number of hairs that come out provides quantitative information about the rate of telogen shedding. The procedure should be performed on hair that hasn't been washed for 24+ hours to capture accumulated telogen hairs.

Normal results: fewer than 3 hairs extracted from a pull of 50 to 60. More than 6 hairs extracted suggests active telogen effluvium. Microscopic examination of extracted hairs adds diagnostic value, telogen hairs have a distinctive club-shaped root, anagen hairs have an attached pigmented root sheath, and dystrophic hairs (broken shaft, abnormal root) suggest specific pathologies. The technique is reproducible with standardised pressure and consistent technique.

Practical value: positive hair pull tests confirm active shedding and warrant workup for telogen effluvium causes (thyroid, iron, recent stressors, medications). Negative results in patients reporting hair loss suggest either resolved telogen effluvium, slow androgenetic alopecia progression, or perception-only issues. The procedure can be self-administered at home, though interpretation benefits from clinical context. Patients tracking treatment response can use serial hair pull tests as a simple objective measure of shedding rate over time.